use std::collections::VecDeque;


fn main() {
    let mut pq = String::new();
    std::io::stdin().read_line(&mut pq).ok();
    let pq: Vec<f64> = pq.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let p0 = pq[0] / 100.;
    let q = pq[1] / 100.;

    let mut result = 1. / 3.;
    let mut deque = VecDeque::new();
    deque.push_back((1. / 3., 1, p0));
    while let Some((prob, pattern, prevp)) = deque.pop_front() {
        if prob < 1e-12 { continue; }
        let p = match pattern {
                1 => { p0 },
                2 => { (prevp + q).max(0.).min(1.) },
                3 => { (prevp - q).max(0.).min(1.) },
                _ => { unreachable!(); }
            };
        let unused = prob * (1. - p) / 3.;
        let used = prob * p / 2.;
        result += unused;
        result += used;
        deque.push_back((unused, 2, p));
        deque.push_back((used, 3, p));
    }
    println!("{}", result);
}